On 17/02/16 21:44, Matt Ranostay wrote: > On Wed, Feb 17, 2016 at 1:19 PM, Jonathan Cameron <jic23@xxxxxxxxxx> wrote: >> On 15/02/16 15:02, Mark Brown wrote: >>> On Sun, Feb 14, 2016 at 06:40:15PM +0100, Lars-Peter Clausen wrote: >>>> On 02/14/2016 04:02 PM, Jonathan Cameron wrote: >>> >>>>> I'm lost here. Why should changing the storage of the register cache result >>>>> in different behaviour other than in efficiency of access to cached values? >>> >>>> And if there is really a difference this should probably be addressed at the >>>> regmap level. >>> >>> You'd need to make regcache-flat keep track of which cache values are >>> valid either during init (in which case it'd have to read every other >>> register at that time) or at runtime (which would mean extra operations >>> in a fast path). Flat really is special here, there's no reason to use >>> it over a rbtree other than being very sensitive about performance. >>> >>> Please also be aware that if you CC me on an iio patch series there's a >>> good chance I'll just delete it without reading it, for some reason I >>> keep on getting copied on lots of them which have no relevance to me >>> that I'm able to identify. >>> >> Hmm. Not the best documented 'non intuitive case' ever, but fair enough. >> Glad you did pick this one up Mark! >> >> So Matt, the reason those two elements are dropped from being volatile >> is that they never were, but because we were using a flat cache it wasn't >> getting the original values? >> >> If so fair enough I suppose, but please confirm that I've understood this >> correctly + I'll probably expand the patch description somewhat to make it >> clearer why the original was wrong. > > That is correct. Flat cache wasn't getting the on device value without > it being set as volatile. Applied to the togreg branch iio.git - initially pushed out as testing for the autobuilders to play with it. Thanks, Jonathan > > >> >> Jonathan > -- > To unsubscribe from this list: send the line "unsubscribe linux-iio" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
